OXNARD, Calif. -- It took only a moment for the Cowboys' backup quarterback situation, one the team brass had discussed "ad nauseam," during the offseason per executive vice president Stephen Jones, to change.

Backup Kellen Moore broke his right ankle late in team drills during training camp practice Tuesday night. Suddenly, rookie Dak Prescott and former Texas A&M and UTEP QB Jameill Showers are Dallas' only insurance left behind starter Tony Romo -- at least for now.

Told about the diagnosis, Showers said he'd hoped it wouldn't be that severe. Showers signed with Dallas as a rookie free agent following the 2015 draft, but was released at the end of camp. He spent the first 15 weeks of last season on Dallas' practice squad, but was signed to the active roster for Week 16, but was inactive for each of the final two games.

"It's just unfortunate," Showers said. "The d-line pushed the o-lineman right into him as he was throwing. I wasn't sure if it was his knee or his ankle, but it didn't look too good. He's a pretty tough guy. He's never hurt."

Showers said Moore has made an impression on him during their time together in Dallas.

"Smart guy," he said. "One of the smartest football players I've ever been around. He's actually helped me a lot. Protections, I definitely struggled with protections last season. Any questions I had he answered them for me. Great guy."